Taking folic acid before conception and in the early stages of
pregnancy appears to reduce the risk of children developing autism,
a study suggests.The research, carried out among 85,000 children,
found that women who took the supplement, also known to reduce the
risk of spina bifida, were 40 per cent less likely to have a child
suffering from autism.

The researchers found that timing was key,
with folic acid needing to be taken between four weeks before
pregnancy to eight weeks into pregnancy to have an impact on autism
risk.But Scottish campaigners said more research was needed before
official advice could be given to mothers-to-be.Folic acid - also
known as vitamin B9 - is essential for DNA creation and repair in
the human body.Its naturally occurring form, folate, is found in a
number of sources - leafy vegetables, peas, lentils, beans, eggs and
liver - but women planning pregnancy are advised to take supplements
to a sufficient doseage to protect against spina bifida and similar
defects in babies.

The latest study, published in the Journal of the
American Medical Association, also found that the supplement could
help reduce the risk of autism in young children.For the research, a
team from Columbia University in the US, and the Norwegian Institute
of Public Health, studied more than 85,000 babies born in Norway in
the largest study of its type.Mothers were questioned about their
diet and families were questioned over three to ten years to measure
the development of autism spectrum disorders, including autistic
disorder - the most severe form of the condition - and Asperger's
syndrome.

A total of 270 cases of autistic problems were discovered
in the children studied. The researchers found that mothers who took
folic acid supplements in early pregnancy had a 40 per cent reduced
risk of having children with autistic disorder compared to women who
did not take folic acid.

Pal Suren, from the Norwegian Institute of
Public Health, said: "We examined the rate of autism spectrum
disorders in children."There was a dramatic reduction in the risk of
autistic disorder in children born to mothers who took folic acid
supplements."The researchers also looked at whether the risk of
autistic disorder was influenced by the use of other dietary
supplements.They did not find any association between the mother's
use of fish oil supplements - cod liver oil and omega-3 fatty acids -
in early pregnancy and the risk of autistic disorder, and there was
no association for the mother's use of other vitamins and
minerals.

Dr Robert Moffat, national director of the National
Autistic Society (NAS) Scotland, said: "While we welcome studies
such as this, which aim to improve our understanding of autism, far
more research would have to be undertaken across a far greater
geographical area before any definite conclusions can be drawn from
the results.

We therefore urge mothers-to-be to treat this research
with caution until further investigations are done."Ezra Susser,
professor of epidemiology at Columbia University's Mailman School of
Public Health, said: "Our findings extend earlier work on the
significance of folate in brain development and raise the
possibility of an important and inexpensive public health
intervention for reducing the burden of autism spectrum
disorders.

"In recent years, researchers have explored whether folic
acid has other beneficial effects on the development of the brain
and spinal cord of unborn children, as well as the proven effects on
preventing spina bifida.A study of language development in 2011
showed that children whose mothers took folic acid supplements in
early pregnancy had only half the risk of severe "language delay" at
the age of three.